Upgrading wiring harness ofr 02 WRX

[realitycheck]

Hey guys and gals,
I have a few questions for you, I was reading daniel sterns website. Saw he had the relay set up for my bugeye. I was wondering for you that have done this how much improvement does it really make on your stock headlights?
Also which way is better, getting the stuff from daniel stern and making my own harness or getting the whole harnes from suv lights. I want to get the best bang for my buck even if it costs more.

http://www.suvlights.com/product_inf...16313d6b9976a0

Daniel stern is showing $59 for his relay kit plus i'd have to buy wire.

I want to be able to just plug into my factory harness to power the relay, I dont want to have to cut any factory wiring harness.

 

[Alaric Darconville]

Also which way is better, getting the stuff from daniel stern and making my own harness or getting the whole harnes from suv lights. I want to get the best bang for my buck even if it costs more.

Then get the stuff from Daniel Stern, rather than getting the junk from SUVLights.

One advantage to the kits from Daniel Stern is that you save money getting the wiring locally, and you get to choose the gauge rather than getting "heavy duty" wire that may not be substantially better than OEM, and paying a premium on top of that.

How much is your life, the lives of others, and your car worth to you?

 

[realitycheck]

Can you give me a basic idea of how much better light output you get from installing one of these kits?

 

[Alaric Darconville]

You'll only know if you know the voltage drop you are getting. Daniel Stern has the methodology to determine the voltage drop here (Scroll down to "How to measure your voltage drop".)

The change in light output is exponential to the power 3.4.
For the 9007 rated at 1000 lumens (low beam) at 12.8V
10.5V : 510 lumens
11.0V : 597 lumens
11.5V : 695 lumens
12.0V : 803 lumens
12.5V : 923 lumens
12.8V : 1000 lumens ←Rated output voltage
13.0V : 1054 lumens
13.5V : 1198 lumens
14.0V : 1356 lumens ←Rated life voltage
14.5V : 1528 lumens ←shortened life

High beam at 1350 lumens
10.5V : 688 lumens
11.0V : 806 lumens
11.5V : 938 lumens
12.0V : 1084 lumens
12.5V : 1245 lumens
12.8V : 1350 lumens ←Rated output voltage
13.0V : 1423 lumens
13.5V : 1618 lumens
14.0V : 1831 lumens ←Rated life voltage
14.5V : 2063 lumens ←shortened life




You might further do the test with the A/C and fans on max so you can see just how low headlight voltage can drop, even if you work the throttle to take it well above idle.

 

[Alaric Darconville]

Might as well also upgrade the bulbs. You can stay with stock wattage (that's what I feel best recommending just for legality's sake) with the Philips X-Treme Power and get a fantastic upgrade.

Please, please, PLEASE make sure the headlight lenses are clean and polished and that you've aimed them correctly.

 

[realitycheck]

One more question, for now anyway,

When I put new power and ground wire in is 12 gauge sufficient?

 

[Lynx_Arc]

I had a car once I wired up a pair of 100watt halogen off road driving lights.... they were only 55 watt till I changed out the bulbs in them but with metal cases and glass lenses they could have managed 150 watts without trouble. I basically wired them up towards the battery, put the relay by the battery and ran a wire to tap into the high beam circuit so they would only run when the high beams were on AND the switch I put under the dash (lighted switch) was on also. It worked about as good as you can get as I ran 10 gauge wire which handled the ~20 amps fine. Make sure whatever wire you choose handles the wattage at 10v, not 12 or 14v as lights could be on without the alternator running so they could draw more current at lower voltages than normal.

 

[Lynx_Arc]

One more question, for now anyway,

When I put new power and ground wire in is 12 gauge sufficient?

you may be able to just use the frame for ground (if the car has a positive + wiring system and - negative ground). 12 gauge should handle about 10amps maybe more if the run is short, 10 gauge is rated for 15amps.
http://www.powerstream.com/Wire_Size.htm

 

[-Virgil-]

Generally good advice here, but don't use body/chassis grounds. Use an actual wire (of the same gauge you use to feed the lamps) and connect it to an electrically-sound ground (battery negative terminal, alternator housing, either end of an existing ground strap, etc.)

And yes, 12ga is more than plenty.

 

[Alaric Darconville]

Toyota uses a switched-ground system; I don't know if Subaru also does it that way. Daniel Stern will be able to make the best recommendation for the specific connections.

As for the wire gauge, it may cost a little more, but getting the largest gauge the relays and sockets can handle surely isn't a bad idea.

 

[Lynx_Arc]

Generally good advice here, but don't use body/chassis grounds. Use an actual wire (of the same gauge you use to feed the lamps) and connect it to an electrically-sound ground (battery negative terminal, alternator housing, either end of an existing ground strap, etc.)

And yes, 12ga is more than plenty.

using the chassis ground could give you up to an extra 0.2v over 12gauge wire due to the resistance of wire under current as chassis ground properly done is probably like a OOOOOOO gauge wire

 

[tay]

Make sure whatever wire you choose handles the wattage at 10v, not 12 or 14v as lights could be on without the alternator running so they could draw more current at lower voltages than normal.

Incorrect. They will draw additional current if the voltage is higher than the nominal voltage, and reduced current if the voltage is lower than the nominal voltage.

 

[-Virgil-]

using the chassis ground could give you up to an extra 0.2v over 12gauge wire due to the resistance of wire under current as chassis ground properly done is probably like a OOOOOOO gauge wire

I can't tell if you're being thoughtless, ignorant, or sarcastic here.

Make sure whatever wire you choose handles the wattage at 10v, not 12 or 14v as lights could be on without the alternator running so they could draw more current at lower voltages than normal.

Wrong, this is a resistive load and not an electric motor we're discussing here.

 

[CanadianGuy]

They want that much for a relay kit?! Unless you don't know much at all about 12V electrical, it's not terribly hard to make this kit yourself. I think the idea was more geared towards the guys with the old cars, like 1960s-70s (or even older, but that's going back to generator/6V days).

The problem with the older cars (specifically chevy's, not sure which others may have done it this way) was that the headlight circuit (along with many others IIRC) takes some long weird path through the horn relay, so that by the time the voltage reaches the bulb it was something like 10-11V even while running! There was that much of a voltage drop.

I'm going to assume newer cars are somewhat more efficient at getting power to the bulbs. You may see a slight increase in brightness, but probably nothing as dramatic as the old cars.

Good luck!

 

[Lynx_Arc]

I can't tell if you're being thoughtless, ignorant, or sarcastic here.



Wrong, this is a resistive load and not an electric motor we're discussing here.

using the calculator on this page HERE
and inputting 12 gauge, 12v, 10amps and 6 foot of wiring (could be longer if chassis ground isn't used you get 0.196 voltage drop, for 9 feet the drop is close to 0.3v. while this isn't huge it can effect the brightness while a chassis ground would be considered an enormous gauge of wire using the calculator with a 4/0 gauge setting (largest listed the drop is only 0.012v for 12 feet which is essentially 0 for all purposes and if that is half the trip to/from the battery that basically makes the drop half. As for the resistive load etc, for all practical purposes when the battery is heavily loaded and the alternator is not operating any load added will make any voltage drop seem very significant in terms of brightness so larger wire will help even more when you are starved for power hence my advice. They don't put larger cables on car batteries for no reason, the voltage drop is more critical at starting voltages than at charging voltages even if the resistive load is less in voltage at that level the headroom for operating is considerably cramped as lights do not operate as bright at 12v as they do at 14 and even less bright at voltages of 10-11v. I had a pair of 100watt halogens on a car and you could certainly tell the brightness when you revved the engine which spun the alternator faster. IMO if you are wanting maximum performance, you go with heavier wiring as I did because I started with 55watts and upgraded to 100watts and the wire handled larger bulbs with ease. They make 135 and 150 watt bulbs for some offroad lights if the bulb housings/lenses can handle them (heat) with larger wire it would just be a swap to upgrade.

 

[Alaric Darconville]

They want that much for a relay kit?! Unless you don't know much at all about 12V electrical, it's not terribly hard to make this kit yourself. I think the idea was more geared towards the guys with the old cars, like 1960s-70s (or even older, but that's going back to generator/6V days).

Sure, you can do that yourself, but you want to be sure you're getting very high quality parts and not just some cheap thing in a blister pack at Autozone.

You're also getting competent consultation. You don't get that from a blister pack. You don't get that kind of service from SUVlights.

The problem with the older cars (specifically chevy's, not sure which others may have done it this way) was that the headlight circuit (along with many others IIRC) takes some long weird path through the horn relay, so that by the time the voltage reaches the bulb it was something like 10-11V even while running! There was that much of a voltage drop.

My '65 Dart (12V, negative ground) had much heavier gauge wire than my '95 Previa or my '01 Corolla. Although I never measured it, I don't think I'd have had that kind of voltage drop in it like you describe.

I'm going to assume newer cars are somewhat more efficient at getting power to the bulbs. You may see a slight increase in brightness, but probably nothing as dramatic as the old cars.

There's always "assumptions". No matter the "efficiency", there's still the problem of the usage of 18 or 20ga wire by the OEMs.

 

[-Virgil-]

They want that much for a relay kit?! Unless you don't know much at all about 12V electrical, it's not terribly hard to make this kit yourself.

Relays: Very easy if you don't care about quality or reliability; not very hard if you do care about quality and reliability.

Appropriate fuse holders: easy

Good quality headlight bulb sockets made for use with large-gauge wire: very difficult.

Good quality headlight bulb plugs to interface with the car's own sockets so they don't have to be cut off: very difficult.

None of it's impossible, but what's your time worth? Seems to me the alternatives are (A) do a halfway job with pathetic factory (or factory-type) thin-gauge-wired headlight sockets and hacked (or hacked off) interface, or (B) run all over town and/or place multiple online orders with multiple shipping charges to chase down all the components, or (C) just order the complete parts package from Stern or an equivalent supplier and have it all arrive in one go.

I'm going to assume newer cars are somewhat more efficient at getting power to the bulbs.

Your guess is wrong.

 

[-Virgil-]

using the calculator on this page

Anyone can pick up a tool and use it. That doesn't mean they know what they're doing or how to use the tool.

inputting 12 gauge, 12v, 10amps and 6 foot of wiring (could be longer if chassis ground isn't used you get 0.196 voltage drop, for 9 feet the drop is close to 0.3v.

You cannot determine the voltage drop through a headlight circuit by typing numbers into a calculator on the web; you have to go out to the driveway, raise the hood and actually measure it.

a chassis ground would be considered an enormous gauge of wire

Sure, in the ideal world of perfect conductors and perfect connections. I wish we lived in that world, but we don't.

They don't put larger cables on car batteries for no reason

Right. They do it because starter motors draw a great deal of current.

I had a pair of 100watt halogens on a car and you could certainly tell the brightness when you revved the engine which spun the alternator faster.

Right. But that doesn't support your claim that the current in the headlight circuit will be higher at lower voltage. It won't be.

IMO if you are wanting maximum performance, you go with heavier wiring

Of course you do. That's not really under debate.

They make 135 and 150 watt bulbs

Yes, but they're a dumb idea to use. The larger filament they require not only has lower luminance, but also defocuses the beam (shorter seeing distance) and floods the foreground with light (which constricts your eyes' pupils, further reducing your distance seeing acuity).

 

[Lynx_Arc]

Anyone can pick up a tool and use it. That doesn't mean they know what they're doing or how to use the tool.
You cannot determine the voltage drop through a headlight circuit by typing numbers into a calculator on the web; you have to go out to the driveway, raise the hood and actually measure it.

you can figure out the voltage drop through just the wire with the chart and calculator, and figure that there will be other losses but minimizing such losses based upon the data would be intelligent I would think.

Sure, in the ideal world of perfect conductors and perfect connections. I wish we lived in that world, but we don't.

If you use quality connectors and relays the main losses should be in the wire and the light wiring itself as the other parts are short distance so resistance should be minimal.

Right. They do it because starter motors draw a great deal of current.

they also put larger cables on alternators because lots of current flows through them and larger cables to your air conditioner and other devices drawing current.

Right. But that doesn't support your claim that the current in the headlight circuit will be higher at lower voltage. It won't be.

I never said the current would be higher, some people design their lighting based on 14v, some 12v, if you do your specs on wire sizes based upon currents at less than 12v (engine off with an electrical load other than lights added in) the larger wiring will have less current loss at higher voltages also. at a certain voltage the light output will start to change colors and at some point (low voltage) an extra +0.2v could be noticeable, and if +0.4v even more noticeable. This is why they use a relay instead of running the wire all the way to the switch and back to reduce wire resistance (and cost of larger wire vs cost of relays).

Of course you do. That's not really under debate.

yeah debate.... is that like what you use to catch defish?

Yes, but they're a dumb idea to use. The larger filament they require not only has lower luminance, but also defocuses the beam (shorter seeing distance) and floods the foreground with light (which constricts your eyes' pupils, further reducing your distance seeing acuity).

I have a pair of 130 watt H3 bulbs I got for cheap new in box... the filaments run horizontal so the focal point should be about the same as other bulbs with horizontal filaments, you could always install a reflecting cap if possible to capture and use the extra spill from increased output. I didn't have an issue with my 55 to 100 watt upgrade on two pairs of lights on two vehicles. one set was driving lights and the other was larger off road lights that essentially had the output of driving lights with larger deeper reflectors.
and clear glass (no special lenses to redirect output). I sure miss having those lights but my car now doesn't have a good way to mount any. I had to custom make some brackets for one car but I worked at a welding shop at that time so it was easy to manage. The first car the pair of lights came with the relay and wiring kit, the second car I bought the lights singly without wiring and I think I used 10 gauge wire on them and a 20 amp fuse and 30 amp relay. the 100 watts I think were drawing about ~16 amps when I revved the engine probably about ~12-14 amps with the engine off as the battery was small (4 cylinder car). I could hear my 65 amp alternator whine a little when I hit the high beam circuit the relay was tied into when they were on. I remember driving a turnpike and lighting up an entire bridge crossing over it from about 1.2 miles away

 

[-Virgil-]

you can figure out the voltage drop through just the wire with the chart and calculator

Yeah, sorta, but the headlight circuit consists of a lot more than just the wire, so what's the point?

and figure that there will be other losses but minimizing such losses based upon the data would be intelligent I would think

Um, no, that's not intelligent, it's ignorant and thoughtless. You're guessing and making stuff up because you don't know what you're talking about. It's completely transparent and you're not fooling anybody. Best just stop now, admit you don't know what you're talking about (or just keep quiet) and learn from those who do. Your method boils down to "guess, assume, put some numbers into a web-based calculator, ignore everything but the wire, and then guess some more". The right method boils down to "open the hood and measure directly". You seriously can't see why your method is lacking in realistic basis?

If you use quality connectors and relays the main losses should be in the wire and the light wiring itself as the other parts are short distance so resistance should be minimal

Ah-ah-aaah, stay on topic. We're talking about resistance in the unmodified original headlight circuit.

they also put larger cables on alternators because lots of current flows through them and larger cables to your air conditioner and other devices drawing current.

Yeah, and? Nobody's debating that. Stay on topic.

I never said the current would be higher

Yeah, you did, that's exactly what you said. Read back up the thread and see where you said:

Make sure whatever wire you choose handles the wattage at 10v, not 12 or 14v as lights could be on without the alternator running so they could draw more current at lower voltages than normal.

I have a pair of 130 watt H3 bulbs I got for cheap new in box... the filaments run horizontal so the focal point should be about the same

Wrong (more ignorant guessing and assumption).

you could always install a reflecting cap if possible to capture and use the extra spill from increased output.

Babble, babble, babble. There's no such thing as a "reflecting cap" that gives increased output and lets you "use the extra spill", whatever that's supposed to mean.